lcd view all day and night?

archaic0 · 07-03-2007, 10:03 PM

Ok, I've been running my carpc for a few months now and I've come to an impass and wanted some input from users on how they solve this issue.

My screen is too bright at night. Even with the brightness down and video 'muted' the inside of the car glows like a movie set car.

What I mean is that even with a completely black screen the backlight is kicking out too much light to be comfortable.

My screen has a dead pixel and I had decided to replace it so I tried using 20 percent window tint right on the screen. It's a touch screen so I had my concerns, but it worked fine with no damage or effect on the touch sensor.

However, the screen is too dark during the day now and there is a horrible glare. I thought about using tiny that isn't as dark, but the glare issue remains and 20 percent really is perfect for night time use.

At night the glare isn't an issue. Only the brightness and this tint fixed that.

I'm out of ideas at the moment for what to do with the new screen. Leave it alone or tint it?

I had thought maybe I could make a tint overlay like an anti glare screen kind of thing, but I have my doubts about my ability to make one cleanly and that works well.

Has anyone out there come up with anything or do you just all drive around like you're being filmed in a spotlight? *smile*

Or do more expensive screens maybe just have a FAR better black level so that turning the brightness down actually leads to a darker screen?

My screen brightness and contrast controls don't seem to effect the backlight at all, only the video, but even with brightness down to 0 my car glows. Don't get me wrong, the video goes away, but the 'black' screen that is left is very bright and more grey than black.

Do I just keep this screen and swap between it and a new un tinted screen for day use? *smile*

As always, thanks in advance for any input.

turbocad6 · 07-03-2007, 10:39 PM

ok, just a tiny hint of what screen your working with might help

a decent screen should be able to really dim all the way down, if it doesn't it's a direct result of the inverter... if I had a situation like that I would dissasemble it & try to get a better inverter, worse case you may have a brightness knob seperate from the screen, that might not be a bad thing really as it's a convienient way to raise & lower the backlight instead of going through menu's

archaic0 · 07-03-2007, 10:51 PM

Well I'm not afraid to open it up, but knowing what wires to route through the rheostat would be my challenge.

My screen is a generic 8" from eBay. No idea what it's origins are.

On a side note though, even my viewsonic lcd on my desk has this symtom. It can best be seen in a dark room with the 'blank screen' screen saver running. Big glowing panel.

Given that, I'm reluctant to call this a quality issue but rather just a normal side effect of using lcds. I guess I'm just sensative to it where most are not.

turbocad6 · 07-03-2007, 11:35 PM

yeah, really any screen is gonna light up the interior some, I think it's a matter of getting used to it somewhat also. I hate that I can see my screen reflected on the passengers door window at night & I can dim really really low. I have dark tint on the windows & that adds to the night glare a bit too.

archaic0 · 07-04-2007, 01:53 AM

Well before the tint, the screen was just unbearable for night time use. I was just shutting it completely off between times I needed to touch it.

The night time driving I'm doing is mostly highway time between cities, so it's completely black outside which amplifies the problem. In town with city lights and so forth makes it easy enough to live with, but hours in pitch black with a bright white glow in your face destroys your night vision for outside the car and I'd go as far as to say that it even raises the danger level for hitting deer or other animals on the road because I'm less likely to see them in the ditch soon enough to react.

I think I'm going to get to work on the tint screen overlay thing. I need to find a thin and clear base material though because the tint itself is too flimsy to use by itself. I need to make sure it still transmits the touch though for the touch screen.

I'll do some experiments and try to figure something out.

tonystoolroom · 07-04-2007, 09:55 AM

Yes, the LCD manufacturers haven't realized that for car use we need a screen that is bright enough for use in direct sunlight but has a photocell self dimming feature for nighttime use.

My Lilliput 8" TS is useless in direct sunlight, and blinding at night.

tonystoolroom · 07-04-2007, 10:00 AM

I wonder what a 8" Data911 screen costs?

http://www.data911.com/main/display.html

Borte · 07-04-2007, 02:01 PM

I added a red color filter to my screen to reduce the brightness at night. I placed it between the touchscreen and the actual display. That way it would not change the reflections from the screen.

I used red because it is better at night and it also goes perfect with my Audi interior. The only problem is that everything will be shades of red but for me that doesn't do anything since I only use it for music and nav.

Red is also not so much affected at daytime but it would hurt having higher brightness at daytime.

I was trying to find a picture of it but couldn't. I'll post if I find it.

Cheers
Borte

Jamil20 · 07-04-2007, 02:13 PM

Wear sunglasses?

On a serious note, you should be able to adjust the brightness with the controls on the screen, plus the software. I know Road Runner allows you to use a night mode skin to help with the brightness issue. iGuidance also has a night mode skin.

archaic0 · 07-04-2007, 02:26 PM

Quote: Originally Posted by Jamil20

Wear sunglasses?

On a serious note, you should be able to adjust the brightness with the controls on the screen, plus the software. I know Road Runner allows you to use a night mode skin to help with the brightness issue. iGuidance also has a night mode skin.

Well see, like I said in my original post, it's not the 'on' pixels that are the problem. I CAN adjust the brightness of the 'on' pixels no problem with both methods you describe.

BUT, even with every brightness control down to zero, and a blank screen screen saver in effect, the resulting glow from the screen is WAY too bright for pitch black nightime use. The brightness problem isn't with the video itself, but with the backlight of the LCD.

We've all got LCD monitors on our desktop computers, right? You can see what I'm talking about by turning your monitor on, enabling the 'blank screen' screen saver and then turning the lights out and looking at the room. You'll be able to see pretty well even though the screen is 'off'.

I think maybe instead of an overlay piece, I might see if I can't cut a slit on the top part of the screen case and slide in a tint sheet at night like you put a gel in front of a spotlight. Maybe that's an idea...

Borte · 07-04-2007, 02:31 PM

Quote: Originally Posted by archaic0

I think maybe instead of an overlay piece, I might see if I can't cut a slit on the top part of the screen case and slide in a tint sheet at night like you put a gel in front of a spotlight. Maybe that's an idea...

I did this originally (placed the film in front of the screen) but the film (thit sheet in your case) got scratched and worn after a while. That's the reason why I placed it between the touchplate and the screen.

archaic0 · 07-04-2007, 02:34 PM

Well if I do the slide in filter thing maybe I'll be able to slide it between the touchplate and the screen.

Borte · 07-04-2007, 02:35 PM

I don't think thats possible without opening the screen up. It's usually glued together.

Dingo509 · 07-04-2007, 02:39 PM

Im still learning what can and cannot be done. but it is possible to somehow wire a resistor or something similiar into the light tubes? maybe put them on a switch with the normal voltage on one side and the reduced power on the other?

It may be PWM too but you should be able to find out how to reduce that to decrease the backlight.

I think?

Dingo

Curiosity · 07-04-2007, 09:19 PM

There have been a few threads on this over the years. From what I remember, the inverter puts out around 600 to 900 volts and very little power/amps. You need to lower the volts without decreasing amps or frequency. Otherwise you shorten the life span. On my lilliput, I traced the inverter source power and tapped into it, then connected it to the dash dimmer through a relay.

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